organized_contracts/2f/2f19579bed01c35c49a32a884d899227da5eb25893d63817413dd88c132cb5ee/main.sol

// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023.

// Sources flattened with hardhat v2.11.2 https://hardhat.org

// File erc721a-upgradeable/contracts/[email protected]

// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs

pragma solidity ^0.8.4;

/**

 * @dev Interface of ERC721A.

 */
interface IERC721AUpgradeable {
    /**

     * The caller must own the token or be an approved operator.

     */
    error ApprovalCallerNotOwnerNorApproved();

    /**

     * The token does not exist.

     */
    error ApprovalQueryForNonexistentToken();

    /**

     * Cannot query the balance for the zero address.

     */
    error BalanceQueryForZeroAddress();

    /**

     * Cannot mint to the zero address.

     */
    error MintToZeroAddress();

    /**

     * The quantity of tokens minted must be more than zero.

     */
    error MintZeroQuantity();

    /**

     * The token does not exist.

     */
    error OwnerQueryForNonexistentToken();

    /**

     * The caller must own the token or be an approved operator.

     */
    error TransferCallerNotOwnerNorApproved();

    /**

     * The token must be owned by `from`.

     */
    error TransferFromIncorrectOwner();

    /**

     * Cannot safely transfer to a contract that does not implement the

     * ERC721Receiver interface.

     */
    error TransferToNonERC721ReceiverImplementer();

    /**

     * Cannot transfer to the zero address.

     */
    error TransferToZeroAddress();

    /**

     * The token does not exist.

     */
    error URIQueryForNonexistentToken();

    /**

     * The `quantity` minted with ERC2309 exceeds the safety limit.

     */
    error MintERC2309QuantityExceedsLimit();

    /**

     * The `extraData` cannot be set on an unintialized ownership slot.

     */
    error OwnershipNotInitializedForExtraData();

    // =============================================================
    //                            STRUCTS
    // =============================================================

    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Stores the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
        // Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
        uint24 extraData;
    }

    // =============================================================
    //                         TOKEN COUNTERS
    // =============================================================

    /**

     * @dev Returns the total number of tokens in existence.

     * Burned tokens will reduce the count.

     * To get the total number of tokens minted, please see {_totalMinted}.

     */
    function totalSupply() external view returns (uint256);

    // =============================================================
    //                            IERC165
    // =============================================================

    /**

     * @dev Returns true if this contract implements the interface defined by

     * `interfaceId`. See the corresponding

     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)

     * to learn more about how these ids are created.

     *

     * This function call must use less than 30000 gas.

     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);

    // =============================================================
    //                            IERC721
    // =============================================================

    /**

     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.

     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**

     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.

     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**

     * @dev Emitted when `owner` enables or disables

     * (`approved`) `operator` to manage all of its assets.

     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**

     * @dev Returns the number of tokens in `owner`'s account.

     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**

     * @dev Returns the owner of the `tokenId` token.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**

     * @dev Safely transfers `tokenId` token from `from` to `to`,

     * checking first that contract recipients are aware of the ERC721 protocol

     * to prevent tokens from being forever locked.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must exist and be owned by `from`.

     * - If the caller is not `from`, it must be have been allowed to move

     * this token by either {approve} or {setApprovalForAll}.

     * - If `to` refers to a smart contract, it must implement

     * {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.

     *

     * Emits a {Transfer} event.

     */
    function safeTransferFrom(

        address from,

        address to,

        uint256 tokenId,

        bytes calldata data

    ) external payable;

    /**

     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.

     */
    function safeTransferFrom(

        address from,

        address to,

        uint256 tokenId

    ) external payable;

    /**

     * @dev Transfers `tokenId` from `from` to `to`.

     *

     * WARNING: Usage of this method is discouraged, use {safeTransferFrom}

     * whenever possible.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must be owned by `from`.

     * - If the caller is not `from`, it must be approved to move this token

     * by either {approve} or {setApprovalForAll}.

     *

     * Emits a {Transfer} event.

     */
    function transferFrom(

        address from,

        address to,

        uint256 tokenId

    ) external payable;

    /**

     * @dev Gives permission to `to` to transfer `tokenId` token to another account.

     * The approval is cleared when the token is transferred.

     *

     * Only a single account can be approved at a time, so approving the

     * zero address clears previous approvals.

     *

     * Requirements:

     *

     * - The caller must own the token or be an approved operator.

     * - `tokenId` must exist.

     *

     * Emits an {Approval} event.

     */
    function approve(address to, uint256 tokenId) external payable;

    /**

     * @dev Approve or remove `operator` as an operator for the caller.

     * Operators can call {transferFrom} or {safeTransferFrom}

     * for any token owned by the caller.

     *

     * Requirements:

     *

     * - The `operator` cannot be the caller.

     *

     * Emits an {ApprovalForAll} event.

     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**

     * @dev Returns the account approved for `tokenId` token.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**

     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.

     *

     * See {setApprovalForAll}.

     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**

     * @dev Returns the token collection name.

     */
    function name() external view returns (string memory);

    /**

     * @dev Returns the token collection symbol.

     */
    function symbol() external view returns (string memory);

    /**

     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.

     */
    function tokenURI(uint256 tokenId) external view returns (string memory);

    // =============================================================
    //                           IERC2309
    // =============================================================

    /**

     * @dev Emitted when tokens in `fromTokenId` to `toTokenId`

     * (inclusive) is transferred from `from` to `to`, as defined in the

     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.

     *

     * See {_mintERC2309} for more details.

     */
    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}


// File erc721a-upgradeable/contracts/[email protected]

 

pragma solidity ^0.8.0;

library ERC721AStorage {
    // Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).
    struct TokenApprovalRef {
        address value;
    }

    struct Layout {
        // =============================================================
        //                            STORAGE
        // =============================================================

        // The next token ID to be minted.
        uint256 _currentIndex;
        // The number of tokens burned.
        uint256 _burnCounter;
        // Token name
        string _name;
        // Token symbol
        string _symbol;
        // Mapping from token ID to ownership details
        // An empty struct value does not necessarily mean the token is unowned.
        // See {_packedOwnershipOf} implementation for details.
        //
        // Bits Layout:
        // - [0..159]   `addr`
        // - [160..223] `startTimestamp`
        // - [224]      `burned`
        // - [225]      `nextInitialized`
        // - [232..255] `extraData`
        mapping(uint256 => uint256) _packedOwnerships;
        // Mapping owner address to address data.
        //
        // Bits Layout:
        // - [0..63]    `balance`
        // - [64..127]  `numberMinted`
        // - [128..191] `numberBurned`
        // - [192..255] `aux`
        mapping(address => uint256) _packedAddressData;
        // Mapping from token ID to approved address.
        mapping(uint256 => ERC721AStorage.TokenApprovalRef) _tokenApprovals;
        // Mapping from owner to operator approvals
        mapping(address => mapping(address => bool)) _operatorApprovals;
    }

    bytes32 internal constant STORAGE_SLOT = keccak256('ERC721A.contracts.storage.ERC721A');

    function layout() internal pure returns (Layout storage l) {
        bytes32 slot = STORAGE_SLOT;
        assembly {
            l.slot := slot
        }
    }
}


// File erc721a-upgradeable/contracts/[email protected]

 

pragma solidity ^0.8.0;

/**

 * @dev This is a base storage for the  initialization function for upgradeable diamond facet contracts

 **/

library ERC721A__InitializableStorage {
    struct Layout {
        /*

         * Indicates that the contract has been initialized.

         */
        bool _initialized;
        /*

         * Indicates that the contract is in the process of being initialized.

         */
        bool _initializing;
    }

    bytes32 internal constant STORAGE_SLOT = keccak256('ERC721A.contracts.storage.initializable.facet');

    function layout() internal pure returns (Layout storage l) {
        bytes32 slot = STORAGE_SLOT;
        assembly {
            l.slot := slot
        }
    }
}


// File erc721a-upgradeable/contracts/[email protected]

 
pragma solidity ^0.8.0;

/**

 * @dev This is a base contract to aid in writing upgradeable diamond facet contracts, or any kind of contract that will be deployed

 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an

 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer

 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.

 *

 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as

 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.

 *

 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure

 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.

 */

abstract contract ERC721A__Initializable {
    using ERC721A__InitializableStorage for ERC721A__InitializableStorage.Layout;

    /**

     * @dev Modifier to protect an initializer function from being invoked twice.

     */
    modifier initializerERC721A() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(
            ERC721A__InitializableStorage.layout()._initializing
                ? _isConstructor()
                : !ERC721A__InitializableStorage.layout()._initialized,
            'ERC721A__Initializable: contract is already initialized'
        );

        bool isTopLevelCall = !ERC721A__InitializableStorage.layout()._initializing;
        if (isTopLevelCall) {
            ERC721A__InitializableStorage.layout()._initializing = true;
            ERC721A__InitializableStorage.layout()._initialized = true;
        }

        _;

        if (isTopLevelCall) {
            ERC721A__InitializableStorage.layout()._initializing = false;
        }
    }

    /**

     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the

     * {initializer} modifier, directly or indirectly.

     */
    modifier onlyInitializingERC721A() {
        require(
            ERC721A__InitializableStorage.layout()._initializing,
            'ERC721A__Initializable: contract is not initializing'
        );
        _;
    }

    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        // extcodesize checks the size of the code stored in an address, and
        // address returns the current address. Since the code is still not
        // deployed when running a constructor, any checks on its code size will
        // yield zero, making it an effective way to detect if a contract is
        // under construction or not.
        address self = address(this);
        uint256 cs;
        assembly {
            cs := extcodesize(self)
        }
        return cs == 0;
    }
}


// File erc721a-upgradeable/contracts/[email protected]

 
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs

pragma solidity ^0.8.4;



/**

 * @dev Interface of ERC721 token receiver.

 */
interface ERC721A__IERC721ReceiverUpgradeable {
    function onERC721Received(

        address operator,

        address from,

        uint256 tokenId,

        bytes calldata data

    ) external returns (bytes4);
}

/**

 * @title ERC721A

 *

 * @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)

 * Non-Fungible Token Standard, including the Metadata extension.

 * Optimized for lower gas during batch mints.

 *

 * Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)

 * starting from `_startTokenId()`.

 *

 * Assumptions:

 *

 * - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.

 * - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).

 */
contract ERC721AUpgradeable is ERC721A__Initializable, IERC721AUpgradeable {
    using ERC721AStorage for ERC721AStorage.Layout;

    // =============================================================
    //                           CONSTANTS
    // =============================================================

    // Mask of an entry in packed address data.
    uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

    // The bit position of `numberMinted` in packed address data.
    uint256 private constant _BITPOS_NUMBER_MINTED = 64;

    // The bit position of `numberBurned` in packed address data.
    uint256 private constant _BITPOS_NUMBER_BURNED = 128;

    // The bit position of `aux` in packed address data.
    uint256 private constant _BITPOS_AUX = 192;

    // Mask of all 256 bits in packed address data except the 64 bits for `aux`.
    uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;

    // The bit position of `startTimestamp` in packed ownership.
    uint256 private constant _BITPOS_START_TIMESTAMP = 160;

    // The bit mask of the `burned` bit in packed ownership.
    uint256 private constant _BITMASK_BURNED = 1 << 224;

    // The bit position of the `nextInitialized` bit in packed ownership.
    uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;

    // The bit mask of the `nextInitialized` bit in packed ownership.
    uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;

    // The bit position of `extraData` in packed ownership.
    uint256 private constant _BITPOS_EXTRA_DATA = 232;

    // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
    uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;

    // The mask of the lower 160 bits for addresses.
    uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;

    // The maximum `quantity` that can be minted with {_mintERC2309}.
    // This limit is to prevent overflows on the address data entries.
    // For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
    // is required to cause an overflow, which is unrealistic.
    uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;

    // The `Transfer` event signature is given by:
    // `keccak256(bytes("Transfer(address,address,uint256)"))`.
    bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
        0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;

    // =============================================================
    //                          CONSTRUCTOR
    // =============================================================

    function __ERC721A_init(string memory name_, string memory symbol_) internal onlyInitializingERC721A {
        __ERC721A_init_unchained(name_, symbol_);
    }

    function __ERC721A_init_unchained(string memory name_, string memory symbol_) internal onlyInitializingERC721A {
        ERC721AStorage.layout()._name = name_;
        ERC721AStorage.layout()._symbol = symbol_;
        ERC721AStorage.layout()._currentIndex = _startTokenId();
    }

    // =============================================================
    //                   TOKEN COUNTING OPERATIONS
    // =============================================================

    /**

     * @dev Returns the starting token ID.

     * To change the starting token ID, please override this function.

     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**

     * @dev Returns the next token ID to be minted.

     */
    function _nextTokenId() internal view virtual returns (uint256) {
        return ERC721AStorage.layout()._currentIndex;
    }

    /**

     * @dev Returns the total number of tokens in existence.

     * Burned tokens will reduce the count.

     * To get the total number of tokens minted, please see {_totalMinted}.

     */
    function totalSupply() public view virtual override returns (uint256) {
        // Counter underflow is impossible as _burnCounter cannot be incremented
        // more than `_currentIndex - _startTokenId()` times.
        unchecked {
            return ERC721AStorage.layout()._currentIndex - ERC721AStorage.layout()._burnCounter - _startTokenId();
        }
    }

    /**

     * @dev Returns the total amount of tokens minted in the contract.

     */
    function _totalMinted() internal view virtual returns (uint256) {
        // Counter underflow is impossible as `_currentIndex` does not decrement,
        // and it is initialized to `_startTokenId()`.
        unchecked {
            return ERC721AStorage.layout()._currentIndex - _startTokenId();
        }
    }

    /**

     * @dev Returns the total number of tokens burned.

     */
    function _totalBurned() internal view virtual returns (uint256) {
        return ERC721AStorage.layout()._burnCounter;
    }

    // =============================================================
    //                    ADDRESS DATA OPERATIONS
    // =============================================================

    /**

     * @dev Returns the number of tokens in `owner`'s account.

     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();
        return ERC721AStorage.layout()._packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**

     * Returns the number of tokens minted by `owner`.

     */
    function _numberMinted(address owner) internal view returns (uint256) {
        return
            (ERC721AStorage.layout()._packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**

     * Returns the number of tokens burned by or on behalf of `owner`.

     */
    function _numberBurned(address owner) internal view returns (uint256) {
        return
            (ERC721AStorage.layout()._packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**

     * Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).

     */
    function _getAux(address owner) internal view returns (uint64) {
        return uint64(ERC721AStorage.layout()._packedAddressData[owner] >> _BITPOS_AUX);
    }

    /**

     * Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).

     * If there are multiple variables, please pack them into a uint64.

     */
    function _setAux(address owner, uint64 aux) internal virtual {
        uint256 packed = ERC721AStorage.layout()._packedAddressData[owner];
        uint256 auxCasted;
        // Cast `aux` with assembly to avoid redundant masking.
        assembly {
            auxCasted := aux
        }
        packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
        ERC721AStorage.layout()._packedAddressData[owner] = packed;
    }

    // =============================================================
    //                            IERC165
    // =============================================================

    /**

     * @dev Returns true if this contract implements the interface defined by

     * `interfaceId`. See the corresponding

     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)

     * to learn more about how these ids are created.

     *

     * This function call must use less than 30000 gas.

     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        // The interface IDs are constants representing the first 4 bytes
        // of the XOR of all function selectors in the interface.
        // See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
        // (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
        return
            interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
            interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
            interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
    }

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**

     * @dev Returns the token collection name.

     */
    function name() public view virtual override returns (string memory) {
        return ERC721AStorage.layout()._name;
    }

    /**

     * @dev Returns the token collection symbol.

     */
    function symbol() public view virtual override returns (string memory) {
        return ERC721AStorage.layout()._symbol;
    }

    /**

     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.

     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

        string memory baseURI = _baseURI();
        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';
    }

    /**

     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each

     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty

     * by default, it can be overridden in child contracts.

     */
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    // =============================================================
    //                     OWNERSHIPS OPERATIONS
    // =============================================================

    /**

     * @dev Returns the owner of the `tokenId` token.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }

    /**

     * @dev Gas spent here starts off proportional to the maximum mint batch size.

     * It gradually moves to O(1) as tokens get transferred around over time.

     */
    function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }

    /**

     * @dev Returns the unpacked `TokenOwnership` struct at `index`.

     */
    function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(ERC721AStorage.layout()._packedOwnerships[index]);
    }

    /**

     * @dev Initializes the ownership slot minted at `index` for efficiency purposes.

     */
    function _initializeOwnershipAt(uint256 index) internal virtual {
        if (ERC721AStorage.layout()._packedOwnerships[index] == 0) {
            ERC721AStorage.layout()._packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }

    /**

     * Returns the packed ownership data of `tokenId`.

     */
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256 packed) {
        if (_startTokenId() <= tokenId) {
            packed = ERC721AStorage.layout()._packedOwnerships[tokenId];
            // If not burned.
            if (packed & _BITMASK_BURNED == 0) {
                // If the data at the starting slot does not exist, start the scan.
                if (packed == 0) {
                    if (tokenId >= ERC721AStorage.layout()._currentIndex) revert OwnerQueryForNonexistentToken();
                    // Invariant:
                    // There will always be an initialized ownership slot
                    // (i.e. `ownership.addr != address(0) && ownership.burned == false`)
                    // before an unintialized ownership slot
                    // (i.e. `ownership.addr == address(0) && ownership.burned == false`)
                    // Hence, `tokenId` will not underflow.
                    //
                    // We can directly compare the packed value.
                    // If the address is zero, packed will be zero.
                    for (;;) {
                        unchecked {
                            packed = ERC721AStorage.layout()._packedOwnerships[--tokenId];
                        }
                        if (packed == 0) continue;
                        return packed;
                    }
                }
                // Otherwise, the data exists and is not burned. We can skip the scan.
                // This is possible because we have already achieved the target condition.
                // This saves 2143 gas on transfers of initialized tokens.
                return packed;
            }
        }
        revert OwnerQueryForNonexistentToken();
    }

    /**

     * @dev Returns the unpacked `TokenOwnership` struct from `packed`.

     */
    function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
        ownership.addr = address(uint160(packed));
        ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
        ownership.burned = packed & _BITMASK_BURNED != 0;
        ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
    }

    /**

     * @dev Packs ownership data into a single uint256.

     */
    function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
        assembly {
            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
            // `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
            result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
        }
    }

    /**

     * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.

     */
    function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
        // For branchless setting of the `nextInitialized` flag.
        assembly {
            // `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
            result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
        }
    }

    // =============================================================
    //                      APPROVAL OPERATIONS
    // =============================================================

    /**

     * @dev Gives permission to `to` to transfer `tokenId` token to another account. See {ERC721A-_approve}.

     *

     * Requirements:

     *

     * - The caller must own the token or be an approved operator.

     */
    function approve(address to, uint256 tokenId) public payable virtual override {
        _approve(to, tokenId, true);
    }

    /**

     * @dev Returns the account approved for `tokenId` token.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return ERC721AStorage.layout()._tokenApprovals[tokenId].value;
    }

    /**

     * @dev Approve or remove `operator` as an operator for the caller.

     * Operators can call {transferFrom} or {safeTransferFrom}

     * for any token owned by the caller.

     *

     * Requirements:

     *

     * - The `operator` cannot be the caller.

     *

     * Emits an {ApprovalForAll} event.

     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        ERC721AStorage.layout()._operatorApprovals[_msgSenderERC721A()][operator] = approved;
        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
    }

    /**

     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.

     *

     * See {setApprovalForAll}.

     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return ERC721AStorage.layout()._operatorApprovals[owner][operator];
    }

    /**

     * @dev Returns whether `tokenId` exists.

     *

     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.

     *

     * Tokens start existing when they are minted. See {_mint}.

     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return
            _startTokenId() <= tokenId &&
            tokenId < ERC721AStorage.layout()._currentIndex && // If within bounds,
            ERC721AStorage.layout()._packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
    }

    /**

     * @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.

     */
    function _isSenderApprovedOrOwner(
        address approvedAddress,
        address owner,
        address msgSender
    ) private pure returns (bool result) {
        assembly {
            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
            // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
            msgSender := and(msgSender, _BITMASK_ADDRESS)
            // `msgSender == owner || msgSender == approvedAddress`.
            result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
        }
    }

    /**

     * @dev Returns the storage slot and value for the approved address of `tokenId`.

     */
    function _getApprovedSlotAndAddress(uint256 tokenId)
        private

        view

        returns (uint256 approvedAddressSlot, address approvedAddress)
    {
        ERC721AStorage.TokenApprovalRef storage tokenApproval = ERC721AStorage.layout()._tokenApprovals[tokenId];
        // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
        assembly {
            approvedAddressSlot := tokenApproval.slot
            approvedAddress := sload(approvedAddressSlot)
        }
    }

    // =============================================================
    //                      TRANSFER OPERATIONS
    // =============================================================

    /**

     * @dev Transfers `tokenId` from `from` to `to`.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must be owned by `from`.

     * - If the caller is not `from`, it must be approved to move this token

     * by either {approve} or {setApprovalForAll}.

     *

     * Emits a {Transfer} event.

     */
    function transferFrom(

        address from,

        address to,

        uint256 tokenId

    ) public payable virtual override {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        // The nested ifs save around 20+ gas over a compound boolean condition.
        if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
            if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();

        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
                // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
        unchecked {
            // We can directly increment and decrement the balances.
            --ERC721AStorage.layout()._packedAddressData[from]; // Updates: `balance -= 1`.
            ++ERC721AStorage.layout()._packedAddressData[to]; // Updates: `balance += 1`.

            // Updates:
            // - `address` to the next owner.
            // - `startTimestamp` to the timestamp of transfering.
            // - `burned` to `false`.
            // - `nextInitialized` to `true`.
            ERC721AStorage.layout()._packedOwnerships[tokenId] = _packOwnershipData(
                to,
                _BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
            );

            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                // If the next slot's address is zero and not burned (i.e. packed value is zero).
                if (ERC721AStorage.layout()._packedOwnerships[nextTokenId] == 0) {
                    // If the next slot is within bounds.
                    if (nextTokenId != ERC721AStorage.layout()._currentIndex) {
                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                        ERC721AStorage.layout()._packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    /**

     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.

     */
    function safeTransferFrom(

        address from,

        address to,

        uint256 tokenId

    ) public payable virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    /**

     * @dev Safely transfers `tokenId` token from `from` to `to`.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must exist and be owned by `from`.

     * - If the caller is not `from`, it must be approved to move this token

     * by either {approve} or {setApprovalForAll}.

     * - If `to` refers to a smart contract, it must implement

     * {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.

     *

     * Emits a {Transfer} event.

     */
    function safeTransferFrom(

        address from,

        address to,

        uint256 tokenId,

        bytes memory _data

    ) public payable virtual override {
        transferFrom(from, to, tokenId);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
    }

    /**

     * @dev Hook that is called before a set of serially-ordered token IDs

     * are about to be transferred. This includes minting.

     * And also called before burning one token.

     *

     * `startTokenId` - the first token ID to be transferred.

     * `quantity` - the amount to be transferred.

     *

     * Calling conditions:

     *

     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be

     * transferred to `to`.

     * - When `from` is zero, `tokenId` will be minted for `to`.

     * - When `to` is zero, `tokenId` will be burned by `from`.

     * - `from` and `to` are never both zero.

     */
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**

     * @dev Hook that is called after a set of serially-ordered token IDs

     * have been transferred. This includes minting.

     * And also called after one token has been burned.

     *

     * `startTokenId` - the first token ID to be transferred.

     * `quantity` - the amount to be transferred.

     *

     * Calling conditions:

     *

     * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been

     * transferred to `to`.

     * - When `from` is zero, `tokenId` has been minted for `to`.

     * - When `to` is zero, `tokenId` has been burned by `from`.

     * - `from` and `to` are never both zero.

     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**

     * @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.

     *

     * `from` - Previous owner of the given token ID.

     * `to` - Target address that will receive the token.

     * `tokenId` - Token ID to be transferred.

     * `_data` - Optional data to send along with the call.

     *

     * Returns whether the call correctly returned the expected magic value.

     */
    function _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try

            ERC721A__IERC721ReceiverUpgradeable(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data)

        returns (bytes4 retval) {
            return retval == ERC721A__IERC721ReceiverUpgradeable(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                revert TransferToNonERC721ReceiverImplementer();
            } else {
                assembly {
                    revert(add(32, reason), mload(reason))
                }
            }
        }
    }

    // =============================================================
    //                        MINT OPERATIONS
    // =============================================================

    /**

     * @dev Mints `quantity` tokens and transfers them to `to`.

     *

     * Requirements:

     *

     * - `to` cannot be the zero address.

     * - `quantity` must be greater than 0.

     *

     * Emits a {Transfer} event for each mint.

     */
    function _mint(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = ERC721AStorage.layout()._currentIndex;
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // `balance` and `numberMinted` have a maximum limit of 2**64.
        // `tokenId` has a maximum limit of 2**256.
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            ERC721AStorage.layout()._packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `quantity == 1`.
            ERC721AStorage.layout()._packedOwnerships[startTokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            uint256 toMasked;
            uint256 end = startTokenId + quantity;

            // Use assembly to loop and emit the `Transfer` event for gas savings.
            // The duplicated `log4` removes an extra check and reduces stack juggling.
            // The assembly, together with the surrounding Solidity code, have been
            // delicately arranged to nudge the compiler into producing optimized opcodes.
            assembly {
                // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
                toMasked := and(to, _BITMASK_ADDRESS)
                // Emit the `Transfer` event.
                log4(
                    0, // Start of data (0, since no data).
                    0, // End of data (0, since no data).
                    _TRANSFER_EVENT_SIGNATURE, // Signature.
                    0, // `address(0)`.
                    toMasked, // `to`.
                    startTokenId // `tokenId`.
                )

                // The `iszero(eq(,))` check ensures that large values of `quantity`
                // that overflows uint256 will make the loop run out of gas.
                // The compiler will optimize the `iszero` away for performance.
                for {
                    let tokenId := add(startTokenId, 1)
                } iszero(eq(tokenId, end)) {
                    tokenId := add(tokenId, 1)
                } {
                    // Emit the `Transfer` event. Similar to above.
                    log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
                }
            }
            if (toMasked == 0) revert MintToZeroAddress();

            ERC721AStorage.layout()._currentIndex = end;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**

     * @dev Mints `quantity` tokens and transfers them to `to`.

     *

     * This function is intended for efficient minting only during contract creation.

     *

     * It emits only one {ConsecutiveTransfer} as defined in

     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),

     * instead of a sequence of {Transfer} event(s).

     *

     * Calling this function outside of contract creation WILL make your contract

     * non-compliant with the ERC721 standard.

     * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309

     * {ConsecutiveTransfer} event is only permissible during contract creation.

     *

     * Requirements:

     *

     * - `to` cannot be the zero address.

     * - `quantity` must be greater than 0.

     *

     * Emits a {ConsecutiveTransfer} event.

     */
    function _mintERC2309(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = ERC721AStorage.layout()._currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();
        if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are unrealistic due to the above check for `quantity` to be below the limit.
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            ERC721AStorage.layout()._packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `quantity == 1`.
            ERC721AStorage.layout()._packedOwnerships[startTokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);

            ERC721AStorage.layout()._currentIndex = startTokenId + quantity;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**

     * @dev Safely mints `quantity` tokens and transfers them to `to`.

     *

     * Requirements:

     *

     * - If `to` refers to a smart contract, it must implement

     * {IERC721Receiver-onERC721Received}, which is called for each safe transfer.

     * - `quantity` must be greater than 0.

     *

     * See {_mint}.

     *

     * Emits a {Transfer} event for each mint.

     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal virtual {
        _mint(to, quantity);

        unchecked {
            if (to.code.length != 0) {
                uint256 end = ERC721AStorage.layout()._currentIndex;
                uint256 index = end - quantity;
                do {
                    if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
                        revert TransferToNonERC721ReceiverImplementer();
                    }
                } while (index < end);
                // Reentrancy protection.
                if (ERC721AStorage.layout()._currentIndex != end) revert();
            }
        }
    }

    /**

     * @dev Equivalent to `_safeMint(to, quantity, '')`.

     */
    function _safeMint(address to, uint256 quantity) internal virtual {
        _safeMint(to, quantity, '');
    }

    // =============================================================
    //                       APPROVAL OPERATIONS
    // =============================================================

    /**

     * @dev Equivalent to `_approve(to, tokenId, false)`.

     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _approve(to, tokenId, false);
    }

    /**

     * @dev Gives permission to `to` to transfer `tokenId` token to another account.

     * The approval is cleared when the token is transferred.

     *

     * Only a single account can be approved at a time, so approving the

     * zero address clears previous approvals.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     *

     * Emits an {Approval} event.

     */
    function _approve(
        address to,
        uint256 tokenId,
        bool approvalCheck
    ) internal virtual {
        address owner = ownerOf(tokenId);

        if (approvalCheck)
            if (_msgSenderERC721A() != owner)
                if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                    revert ApprovalCallerNotOwnerNorApproved();
                }

        ERC721AStorage.layout()._tokenApprovals[tokenId].value = to;
        emit Approval(owner, to, tokenId);
    }

    // =============================================================
    //                        BURN OPERATIONS
    // =============================================================

    /**

     * @dev Equivalent to `_burn(tokenId, false)`.

     */
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }

    /**

     * @dev Destroys `tokenId`.

     * The approval is cleared when the token is burned.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     *

     * Emits a {Transfer} event.

     */
    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        address from = address(uint160(prevOwnershipPacked));

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        if (approvalCheck) {
            // The nested ifs save around 20+ gas over a compound boolean condition.
            if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
                if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
                // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
        unchecked {
            // Updates:
            // - `balance -= 1`.
            // - `numberBurned += 1`.
            //
            // We can directly decrement the balance, and increment the number burned.
            // This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.
            ERC721AStorage.layout()._packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;

            // Updates:
            // - `address` to the last owner.
            // - `startTimestamp` to the timestamp of burning.
            // - `burned` to `true`.
            // - `nextInitialized` to `true`.
            ERC721AStorage.layout()._packedOwnerships[tokenId] = _packOwnershipData(
                from,
                (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
            );

            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                // If the next slot's address is zero and not burned (i.e. packed value is zero).
                if (ERC721AStorage.layout()._packedOwnerships[nextTokenId] == 0) {
                    // If the next slot is within bounds.
                    if (nextTokenId != ERC721AStorage.layout()._currentIndex) {
                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                        ERC721AStorage.layout()._packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);

        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
        unchecked {
            ERC721AStorage.layout()._burnCounter++;
        }
    }

    // =============================================================
    //                     EXTRA DATA OPERATIONS
    // =============================================================

    /**

     * @dev Directly sets the extra data for the ownership data `index`.

     */
    function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
        uint256 packed = ERC721AStorage.layout()._packedOwnerships[index];
        if (packed == 0) revert OwnershipNotInitializedForExtraData();
        uint256 extraDataCasted;
        // Cast `extraData` with assembly to avoid redundant masking.
        assembly {
            extraDataCasted := extraData
        }
        packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
        ERC721AStorage.layout()._packedOwnerships[index] = packed;
    }

    /**

     * @dev Called during each token transfer to set the 24bit `extraData` field.

     * Intended to be overridden by the cosumer contract.

     *

     * `previousExtraData` - the value of `extraData` before transfer.

     *

     * Calling conditions:

     *

     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be

     * transferred to `to`.

     * - When `from` is zero, `tokenId` will be minted for `to`.

     * - When `to` is zero, `tokenId` will be burned by `from`.

     * - `from` and `to` are never both zero.

     */
    function _extraData(
        address from,
        address to,
        uint24 previousExtraData
    ) internal view virtual returns (uint24) {}

    /**

     * @dev Returns the next extra data for the packed ownership data.

     * The returned result is shifted into position.

     */
    function _nextExtraData(
        address from,
        address to,
        uint256 prevOwnershipPacked
    ) private view returns (uint256) {
        uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
        return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
    }

    // =============================================================
    //                       OTHER OPERATIONS
    // =============================================================

    /**

     * @dev Returns the message sender (defaults to `msg.sender`).

     *

     * If you are writing GSN compatible contracts, you need to override this function.

     */
    function _msgSenderERC721A() internal view virtual returns (address) {
        return msg.sender;
    }

    /**

     * @dev Converts a uint256 to its ASCII string decimal representation.

     */
    function _toString(uint256 value) internal pure virtual returns (string memory str) {
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit), but
            // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
            // We will need 1 word for the trailing zeros padding, 1 word for the length,
            // and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
            let m := add(mload(0x40), 0xa0)
            // Update the free memory pointer to allocate.
            mstore(0x40, m)
            // Assign the `str` to the end.
            str := sub(m, 0x20)
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end of the memory to calculate the length later.
            let end := str

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 1)
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                // prettier-ignore
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
            // Store the length.
            mstore(str, length)
        }
    }
}


// File @openzeppelin/contracts-upgradeable/utils/[email protected]

 
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**

 * @dev Collection of functions related to the address type

 */
library AddressUpgradeable {
    /**

     * @dev Returns true if `account` is a contract.

     *

     * [IMPORTANT]

     * ====

     * It is unsafe to assume that an address for which this function returns

     * false is an externally-owned account (EOA) and not a contract.

     *

     * Among others, `isContract` will return false for the following

     * types of addresses:

     *

     *  - an externally-owned account

     *  - a contract in construction

     *  - an address where a contract will be created

     *  - an address where a contract lived, but was destroyed

     * ====

     *

     * [IMPORTANT]

     * ====

     * You shouldn't rely on `isContract` to protect against flash loan attacks!

     *

     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets

     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract

     * constructor.

     * ====

     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**

     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to

     * `recipient`, forwarding all available gas and reverting on errors.

     *

     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost

     * of certain opcodes, possibly making contracts go over the 2300 gas limit

     * imposed by `transfer`, making them unable to receive funds via

     * `transfer`. {sendValue} removes this limitation.

     *

     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].

     *

     * IMPORTANT: because control is transferred to `recipient`, care must be

     * taken to not create reentrancy vulnerabilities. Consider using

     * {ReentrancyGuard} or the

     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].

     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**

     * @dev Performs a Solidity function call using a low level `call`. A

     * plain `call` is an unsafe replacement for a function call: use this

     * function instead.

     *

     * If `target` reverts with a revert reason, it is bubbled up by this

     * function (like regular Solidity function calls).

     *

     * Returns the raw returned data. To convert to the expected return value,

     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].

     *

     * Requirements:

     *

     * - `target` must be a contract.

     * - calling `target` with `data` must not revert.

     *

     * _Available since v3.1._

     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with

     * `errorMessage` as a fallback revert reason when `target` reverts.

     *

     * _Available since v3.1._

     */
    function functionCall(

        address target,

        bytes memory data,

        string memory errorMessage

    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],

     * but also transferring `value` wei to `target`.

     *

     * Requirements:

     *

     * - the calling contract must have an ETH balance of at least `value`.

     * - the called Solidity function must be `payable`.

     *

     * _Available since v3.1._

     */
    function functionCallWithValue(

        address target,

        bytes memory data,

        uint256 value

    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**

     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but

     * with `errorMessage` as a fallback revert reason when `target` reverts.

     *

     * _Available since v3.1._

     */
    function functionCallWithValue(

        address target,

        bytes memory data,

        uint256 value,

        string memory errorMessage

    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],

     * but performing a static call.

     *

     * _Available since v3.3._

     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],

     * but performing a static call.

     *

     * _Available since v3.3._

     */
    function functionStaticCall(

        address target,

        bytes memory data,

        string memory errorMessage

    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**

     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the

     * revert reason using the provided one.

     *

     * _Available since v4.3._

     */
    function verifyCallResult(

        bool success,

        bytes memory returndata,

        string memory errorMessage

    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}


// File @openzeppelin/contracts-upgradeable/proxy/utils/[email protected]

 
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

/**

 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed

 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an

 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer

 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.

 *

 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be

 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in

 * case an upgrade adds a module that needs to be initialized.

 *

 * For example:

 *

 * [.hljs-theme-light.nopadding]

 * ```

 * contract MyToken is ERC20Upgradeable {

 *     function initialize() initializer public {

 *         __ERC20_init("MyToken", "MTK");

 *     }

 * }

 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {

 *     function initializeV2() reinitializer(2) public {

 *         __ERC20Permit_init("MyToken");

 *     }

 * }

 * ```

 *

 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as

 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.

 *

 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure

 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.

 *

 * [CAUTION]

 * ====

 * Avoid leaving a contract uninitialized.

 *

 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation

 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke

 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:

 *

 * [.hljs-theme-light.nopadding]

 * ```

 * /// @custom:oz-upgrades-unsafe-allow constructor

 * constructor() {

 *     _disableInitializers();

 * }

 * ```

 * ====

 */
abstract contract Initializable {
    /**

     * @dev Indicates that the contract has been initialized.

     * @custom:oz-retyped-from bool

     */
    uint8 private _initialized;

    /**

     * @dev Indicates that the contract is in the process of being initialized.

     */
    bool private _initializing;

    /**

     * @dev Triggered when the contract has been initialized or reinitialized.

     */
    event Initialized(uint8 version);

    /**

     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,

     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.

     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**

     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the

     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be

     * used to initialize parent contracts.

     *

     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original

     * initialization step. This is essential to configure modules that are added through upgrades and that require

     * initialization.

     *

     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in

     * a contract, executing them in the right order is up to the developer or operator.

     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**

     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the

     * {initializer} and {reinitializer} modifiers, directly or indirectly.

     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**

     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.

     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized

     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called

     * through proxies.

     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}


// File @openzeppelin/contracts-upgradeable/utils/[email protected]

 
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**

 * @dev Provides information about the current execution context, including the

 * sender of the transaction and its data. While these are generally available

 * via msg.sender and msg.data, they should not be accessed in such a direct

 * manner, since when dealing with meta-transactions the account sending and

 * paying for execution may not be the actual sender (as far as an application

 * is concerned).

 *

 * This contract is only required for intermediate, library-like contracts.

 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    /**

     * @dev This empty reserved space is put in place to allow future versions to add new

     * variables without shifting down storage in the inheritance chain.

     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps

     */
    uint256[50] private __gap;
}


// File @openzeppelin/contracts-upgradeable/access/[email protected]

 
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**

 * @dev Contract module which provides a basic access control mechanism, where

 * there is an account (an owner) that can be granted exclusive access to

 * specific functions.

 *

 * By default, the owner account will be the one that deploys the contract. This

 * can later be changed with {transferOwnership}.

 *

 * This module is used through inheritance. It will make available the modifier

 * `onlyOwner`, which can be applied to your functions to restrict their use to

 * the owner.

 */
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**

     * @dev Initializes the contract setting the deployer as the initial owner.

     */
    function __Ownable_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_msgSender());
    }

    /**

     * @dev Throws if called by any account other than the owner.

     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**

     * @dev Returns the address of the current owner.

     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**

     * @dev Throws if the sender is not the owner.

     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**

     * @dev Leaves the contract without owner. It will not be possible to call

     * `onlyOwner` functions anymore. Can only be called by the current owner.

     *

     * NOTE: Renouncing ownership will leave the contract without an owner,

     * thereby removing any functionality that is only available to the owner.

     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**

     * @dev Transfers ownership of the contract to a new account (`newOwner`).

     * Can only be called by the current owner.

     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**

     * @dev Transfers ownership of the contract to a new account (`newOwner`).

     * Internal function without access restriction.

     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

    /**

     * @dev This empty reserved space is put in place to allow future versions to add new

     * variables without shifting down storage in the inheritance chain.

     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps

     */
    uint256[49] private __gap;
}


// File @openzeppelin/contracts/utils/[email protected]

 
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**

 * @dev String operations.

 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**

     * @dev Converts a `uint256` to its ASCII `string` decimal representation.

     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**

     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.

     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**

     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.

     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**

     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.

     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}


// File @openzeppelin/contracts/token/ERC20/[email protected]

 
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**

 * @dev Interface of the ERC20 standard as defined in the EIP.

 */
interface IERC20 {
    /**

     * @dev Emitted when `value` tokens are moved from one account (`from`) to

     * another (`to`).

     *

     * Note that `value` may be zero.

     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**

     * @dev Emitted when the allowance of a `spender` for an `owner` is set by

     * a call to {approve}. `value` is the new allowance.

     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**

     * @dev Returns the amount of tokens in existence.

     */
    function totalSupply() external view returns (uint256);

    /**

     * @dev Returns the amount of tokens owned by `account`.

     */
    function balanceOf(address account) external view returns (uint256);

    /**

     * @dev Moves `amount` tokens from the caller's account to `to`.

     *

     * Returns a boolean value indicating whether the operation succeeded.

     *

     * Emits a {Transfer} event.

     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**

     * @dev Returns the remaining number of tokens that `spender` will be

     * allowed to spend on behalf of `owner` through {transferFrom}. This is

     * zero by default.

     *

     * This value changes when {approve} or {transferFrom} are called.

     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**

     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.

     *

     * Returns a boolean value indicating whether the operation succeeded.

     *

     * IMPORTANT: Beware that changing an allowance with this method brings the risk

     * that someone may use both the old and the new allowance by unfortunate

     * transaction ordering. One possible solution to mitigate this race

     * condition is to first reduce the spender's allowance to 0 and set the

     * desired value afterwards:

     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729

     *

     * Emits an {Approval} event.

     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**

     * @dev Moves `amount` tokens from `from` to `to` using the

     * allowance mechanism. `amount` is then deducted from the caller's

     * allowance.

     *

     * Returns a boolean value indicating whether the operation succeeded.

     *

     * Emits a {Transfer} event.

     */
    function transferFrom(

        address from,

        address to,

        uint256 amount

    ) external returns (bool);
}


// File @openzeppelin/contracts/interfaces/[email protected]

 
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC20.sol)

pragma solidity ^0.8.0;


// File contracts/721A/The721A.sol

pragma solidity ^0.8.4;

 




contract The721A is ERC721AUpgradeable, OwnableUpgradeable {

    string public uriPrefix = '';
    string public uriSuffix = '';
    bool public revealed = true;
    string public hiddenMetadataUri;
    uint256 public startTokenId;

    uint256 public cost;
    uint256 public maxSupply;
    uint256 public maxMintAmountPerTx;
    bool public paused = true;

    constructor(){}

    struct Inputparams {
        string name_;
        string symbol_;
        address ownerAddress_;
        string _uriPrefix;
        string _uriSuffix;
        uint256 startTokenId_;
        bool revealed_;
        string hiddenMetadataUri_;

        uint256 cost_;
        uint256 maxSupply_;
        uint256 maxMintAmountPerTx_;
        bool paused_;
    }

  modifier mintCompliance(uint256 _mintAmount) {
    require(_mintAmount > 0 && _mintAmount <= maxMintAmountPerTx, 'Invalid mint amount!');
    require(totalSupply() + _mintAmount <= maxSupply, 'Max supply exceeded!');
    _;
  }

  modifier mintPriceCompliance(uint256 _mintAmount) {
    require(msg.value >= cost * _mintAmount, 'Insufficient funds!');
    _;
  }

  function initialize(Inputparams memory inputparams) initializer initializerERC721A public {

    startTokenId = inputparams.startTokenId_;

    __ERC721A_init(inputparams.name_, inputparams.symbol_);
    uriPrefix = inputparams._uriPrefix;
    uriSuffix = inputparams._uriSuffix;
    
    revealed = inputparams.revealed_;
    hiddenMetadataUri = inputparams.hiddenMetadataUri_;

    cost = inputparams.cost_;
    maxSupply = inputparams.maxSupply_;
    maxMintAmountPerTx = inputparams.maxMintAmountPerTx_;
    paused = inputparams.paused_;

    _transferOwnership(inputparams.ownerAddress_);
  }

    function mintForAddress(uint256 _mintAmount, address _receiver) public onlyOwner() {
        require(totalSupply() + _mintAmount <= maxSupply, 'Max supply exceeded!');
        _safeMint(_receiver, _mintAmount);
  }

    function mint(uint256 _mintAmount) public payable mintCompliance(_mintAmount) mintPriceCompliance(_mintAmount) {
        require(!paused, 'The contract is paused!');

        _safeMint(msg.sender, _mintAmount);
    }

    function setUriPrefix(string memory _uriPrefix) public onlyOwner {
        uriPrefix = _uriPrefix;
    }

  function setUriSuffix(string memory _uriSuffix) public onlyOwner {
    uriSuffix = _uriSuffix;
  }

    function tokenURI(uint256 _tokenId) public view virtual override returns (string memory) {
        require(_exists(_tokenId), 'ERC721Metadata: URI query for nonexistent token');
        if (revealed == false) {
            return hiddenMetadataUri;
        }

        string memory currentBaseURI = _baseURI();
        string memory tokenIdInUrl = Strings.toString(_tokenId);

        return bytes(currentBaseURI).length > 0
            ? string(abi.encodePacked(currentBaseURI, tokenIdInUrl, uriSuffix))
            : '';
  }

    function _baseURI() internal view virtual override returns (string memory) {
    return uriPrefix;
  }

  function setCost(uint256 _cost) public onlyOwner {
    cost = _cost;
  }

  function setMaxMintAmountPerTx(uint256 _maxMintAmountPerTx) public onlyOwner {
    maxMintAmountPerTx = _maxMintAmountPerTx;
  }

  function setMaxSupply(uint256 _maxSupply) public onlyOwner {
    maxSupply = _maxSupply;
  }

  function setPaused(bool _state) public onlyOwner {
    paused = _state;
  }

    function setRevealed(bool _state) public onlyOwner {
    revealed = _state;
  }

    function setHiddenMetadataUri(string memory _hiddenMetadataUri) public onlyOwner {
    hiddenMetadataUri = _hiddenMetadataUri;
  }

    function donate() public payable {
    }

      /* Transfer balance of this contract to an account */
    function transferBalance(address payable to, uint256 ammount) onlyOwner() public{
        require(address(this).balance >= ammount);
        to.transfer(ammount);
    }

        /* Transfer any ERC20 balance of this contract to an account */
    function transferERC20Balance(address erc20ContractAddress, address payable to, uint256 ammount) onlyOwner() public{

        IERC20(erc20ContractAddress).transfer(to, ammount);
    }

    function transferOwnership(address newOwner) public override onlyOwner() {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

}